Resinous material



Patented Aug. 17, 1943 I RESINQUS MATERIAL Jacob M. Schantz, Wilmington, DeL, assignor to Hercules Powder Company, Wilmington, Del,

a corporation of Delaware No Drawing. Application February 8, 1941,

Serial No. 378,055

Claims. (crest-10c) This inventionrelates to hydrogenated resins and more specifically to a process for-the improvement of hydrogenated resins and the improved products formed thereby. It still more particularly relates to a process for the improvement of hydrogenated rosin and the improved product formed thereby. I

Natural resins, and in particular, rosin, when subjected to hydrogenation, have given highly desirable products. Of first importance is their ability to resist oxidation. They are,furthermore, pale in color and generally stable-to both heat and sunlight.- Since these materials are widelycompatible and soluble, they may be incorporated in many important commercial products. For example, they may be used in chewing gum, adhesives, metallic resinates, brewers pitches, etc. However, it has been found that even though these hydrogenated resins give highly desirable properties to the'finished product, they are responsible for certain-other objece tionable characteristics. One of the most usually encountered objections is the tendency of the hydrogenated resin to crystallize when used in certain compositions and when used alone as a tendency'of the hydrogenated resin to impart,

taste or odor to the materials with which it comes in contact. This last characteristic is a highly undesirable one incertain potential applications of the material. I acteristic detracts considerably from the desirability otusing hydrogenated natural resins in brewers pitch, chewing gum, etc y I It is an object of this invention to produce a hydrogenated resinous material which will be highly resistant to oxidation and which will not crystallize substantially either when used alone or in a composition in conjunction with other materials.

Another object of this invention is to produce a hydrogenated resinous material which will be capable of retaining its. original elasticity over long periods of time.

A still further objectis to produce a hydrogenated resinous material which is substantially free ofodor and taste imparting substances.

Other objects will appear hereinafter. The objects of thisiinvention are in general accomplished by subjecting a natural resin, which has been hydrogenated to the extent that'the Thus, for example, this char- P unsaturated resin acids contained thereinliave been either partially or'completely saturated, to the furtherprocesses of heat-treatment and removal of the light oils, volatile resin decomposition products, etc. I have found that such a treated hydrogenated resinous'material, such'as, for example, treated hydrogenated rosin, shows highly improved properties over the untreated material. The product is substantially resistant to oxidation; it does not crystallize whenused aloneor in conjunction with other substances. Furthermore, it is substantially non brittle, odorless and tasteless.

My research has shown that when an unsaturated naturalresin is hydrogenated by any of the known methods, a product is obtained which is pale in color, stable to sunlight, stable to heat and resistant to oxidation. The extent to whichsuch a material will possess the aforementioned properties will depend to some degree upon the extent to which the double bonds of the unsaturated resin acids have been removed by treatment with hydrogen. For the purposes of this invention, it has been found that a resin, wherein from about to about 100% of the double bondshave been removed by this reaction,possessessubstantially different properties from those'oiran unhydrogenated resin and may be advantageously used in place of the latter. However, it is preferred to use a resin which has been saturated to the extentof from about to about or the theoretical.

In carryingout the processes embodying my, invention, a quantity of a hydrogenated, natural,

resin is subjected to a heat treatment. The operable range of temperatures for'this step is from about 200 C. to about 375 0.; however, it is preferable to use a temperature within the range of from about 250 C. to about 350 C. Atmospheric pressure is preferably used; however, this operation may be carried out at 'pressures thereabove or below. If a reduced pressure is employed, however, during the heat treatment, it, is important that the pressure ,used be above-that at which substantial distillation of the resin will take place although there may be some distillation of light oils and resin decomposition products during the process. The period of heat treatment may vary within the range of from about A hour to about 48 hours, but preferably within the rangeof from about to about lfi'hours. The heat treatment may be carried out with the heated resin in contact with a gas-which is inert, to the reaction mixway. However, inasmuch as there is always a certain amount of decomposition occurring during distillation, it is preferred to effect the removal of the light oils, resin decomposition products, and odor and taste imparting ingredients by sparging the material with a gas which is inert to the reaction mixture, such as, for ex! ample, carbon dioxide, nitrogen, steam, etc. The: preferred temperature to be used in the spa'rging. operation will vary within the range of from' about 150 C. to aboutv 325 C. Reduced or atmospheric pressure may be employed.

It isdesirable to. conduct the processes: of heat treatment: and: removal of light oils and resin decomposition products in such. a manner that up to about 25% byweight of the resinous material used: is removed. However, it is preferred to operate within the range wherein from about 5 to-about by weight: oi the. resinous material is: removed.

According to my invention, then,. a quantity of a hydrogenated resin, such as; for example, partially or completely hydrogenated rosin, is placed in suitable non-reactive container. The resin. isthen heated to a temperature: of for example, about 300 C. for az period of, for-ere ample, 6 hours, in the presence or, for example, C62. The' melted mass is; then. sparged under vacuum or at atmospheric pressurewith. steam or some other gas which is inertto the reaction mixture. This procedure may be. altered asdesired to produce amaterial havirw somewhat fe-rent physical characteristics. Long heating time with short sparging. time produces amaterial with a low melting point ,anda low acid. rim..- ber. Longq heating with long spargin'g under vacuum yields a product ot medium melting point and a low acid number. .Shortheating time with mediumlong. sparging. time yields. a product with a higher acid. numberanda higher melting point. v

It should be understood tha-t the product which results from the: practice. Qf -thisinventim is characterizedbyits comprising. an. at least. partially hydrogenated, natural resin. which is substantially free from light. oils and volatile resin aciddecomposition products{ turthermorefthe product is characterized by its. comprising. an at least partially h-ydrogenatedlnatural. resin which is substantially free. of odor and taste imparting components.

Where the. term rosin. is used; therein, it should be understood that it includeslb'oth wood and gum. rosin. any of the grades commonly available, also the resin acids obtained from the above rbsinbases, such as, for example, abietic,

Some of these products are removed by the invention is not to be restricted to the use of that material. Other natural resins which can be hydrogenated by any of the well-known processes may, after such treatment, be used. It is also contemplated that the hydrogenated resins may be refined prior to heat treatment, for example, by means of selective solvents; distillation under reduced pressure; adsorbents, such as fullers earth, activated carbon, etc.

It is contemplated, in accordance with the present invention, that plasticizers may be used in conjunction with the treated hydrogenated resins disclosed above. These plasticizers may include paraffin wax, mineral oils, rosin oil, hydrogenated' rosin esters of the lower aliphatic alcohols; etc.; and they may be incorporated in any desired proportion. If rosin oil is used as. plasticizer, it is well to use a rosin oil ob pimari'c, sapini'c, sylvic', etc'., acids", or mixtures thereof.

Any of the resinous productsobtai ned from the members of the genus of tree known as Pinaceae are particularly suitable as a source of the natural resinas. specified herein.

It is further to be noted? that: although hydrogenatedresin: is the prefierred'l ingredient to be employed in the processes described herein,

tainedv from hydrogenated rosin. t should be remembered, however, that in all cases where a plasticizer'is used, care should: be taken that" the added material be highly refined and with minimum: odor and taste.

. There iol low specific examples showing typical methods; of preparing a resinous materialembodying the principles oi, the invention. The hydrogenated rosin employed: in these examples was rosin, the unsaturation of which had been reduced by'approximately 70% of the theoretical for'twc double bonds by combination with. hydrogenin. the known manner; llhis' hydrogenated rosin had: an acidnumber of 168, a color of 5 amber (X onthe. rosin color scale) a miccyanate: value. of about 20-, and a melting point (drop)- ci 79 C}. It will be understood, how ever that. the present invention is not. limited to. the use oi thisparticular-hydrogenated rosin, nor, as has beenhereinbeiore pointedout, is the invention limited tothe use of. any specific hydrogenatect rosin-"in particular. For example, I mayusehydrogenated rosin having a saturation or: about 60 anacid number of 161, a melting point (drop) of 76 C and a. color of 1.0. amber (-X on: the'rosin scale), or hydrogenated rosin havingasaturationof about 60%,. anacid number of L61, a melting. point (drop)- of 3-5 C.,.v and a color of.- L5 amber (WW-lon: the rosin scale). In general, one can employ a hydrogenated rosin which. issaturated to the extent of from about 2.5% to of the theoretical; however, the preferred. range of saturation isfrom about. 50% toabout 90% of thetheoretical.

' ExampZ'e I 'Two. hundred and fifty parts by weight of hydrogenated rosin. were heated at 340 C. to 350 C. and at atmospheric. pressure in an atmosphere of CO2 for 1% hours. The resin was allowed to cool to 25.0" C., 1-5 inches of vacuum was applied, the resin. was sparged withsteam for 12 minutes, and the vacuum maintained for another 15 minutes to remove traces of moisture. The. resin, when cool'edto. C., was poured into a contaiher. The product had a melting point of 58 C.. and. an acidnumber 01130. Further characteristicsof the. product are given. hereinafter.

Example 2.

Three hundred parts by weight of hydrogenated rosin were heated. at 350 C.. to 360 C. and, at atmospheric pressure for 2 hours. The resin was allowed to-cool' to 250 C. and 20 inches of. vacuum applied}. The. resin was sparged with steam for 12. minutes, and. thevacuum. main.- tained. for an additional minutesto remove 'tiaces' o'r moisture. 57' parts 'byweiglit of a light colored viscous oil was obtained as the distillate. "There remained 201"parts by'we'i'ght of product which had a melting point 'o f'52i5" Crand'anacid nuniber of r1155. -Furtherfcharacteristics of-ithe material are -given hereinafter.

' -Ea'amplc 3 7 "Three hundred parts' byweig ht (if-hydrogen- "atedros'in were heated to 250" 0. at atmospheric "pressure. Then the resin spargedwi'th CO2 while the temperature was ra ised to 300 C; over ---a "period ==o"f 2E0 *minutes'. tinned 'spal ing, was allowed tocoilto 230 bver a period of 15 minutes, then the produc't ifv'as The resin, with conpoured into a container. The material had a melting pointof 785 C. and an acid number of 155. Further characteristics follow.

The resinous materials obtained by the above cited examples show definitely improved properties when compared with those of the prior art. They are substantially completely resistant to oxidation, and show practically no tendency to however, the percentage saturation of any other natural resin i referred to, it is based' on the saturation as measured by the absorption of hydrogen by the natural resin when the most ef-' fective catalyst is used, i. e, platinum oxide, for a prolonged period.

It will be understood that the details and exthe processes of heat treatment -at a temperature "witl'iin-the range of from about 250C. to about 350C.fo'r-a'periodof from about /2 hour-to about 10 hours and distillation, saiduistillation being suticientto remove the light "oils and-vola- "tile res'in decomposition products and insufiicient [to remove morethanabout-5'% to about by weight 'otthe 'produ'cti by sparging with a gas I dectimposition products and insufficient to reamples hereinbefore set forth are illustrative only and that the invention as broadly described and claimed is in no way limited thereby.

What I claim and desire to protect by Letters Patent is:

1. The method for improving hydrogenated move more than about 25% by weight of the.

product.

2, The method for improving hydrogenated rosin which includes the steps of subjecting a rosin, which has been saturated with hydrogen to the extent of from about 25% to 100%, to the processes of heat treatment at a temperature within the range of from about 250 C. to about 350 C. for a period of from about hour to about 10 hours and distillation, said distillation being sufiicient to remove the light oils and volatile resin decomposition products and insuflicient to remove more than about 25% by weight of the product.

3. The method for improving hydrogenated rosin which includes the steps of subjecting a rosin, which has been saturated with hydrogen to the extent of from about to about 90%, to

move more than about 25% by weight of the prod vuct, said resin being characterized by having a lower melting point than that of said original hydrogenated natural resin.

5. As a new composition a heat-treated hydrogenated natural resin comprising the residue obtained by distillation of a hydrogenated natural resin obtained from the Pinac'eae tree family, saturated to the extent of between25% and 100% of the double-bonds and subsequentl heat-treated at a temperature within the range of from about 200 C. to about 375 C., the said distillation bein sufficient to remove the light oils and volatile resin decomposition products and insufficient to remove more'than about 25% by weight of the product, said resin being characterized by having a lower melting point than that of said orig inal hydrogenated natural resin.

6. As a new composition a heat-treated hydrogenated natural; resin comprising the residue obtained by distillation of a'hydrogenated rosin saturated to the extent of between 25% and 100% of the double bonds and subsequently heat-treated at a temperature within the range of from about 200 C. to'about 375 C. for a period of from about A; hour to about 48 hours, the said distillation being suflicient to remove the light oils and volatile resin decomposition products and insunicient to remove more than about 25% by weight of the product, said resin being characterized by having a lower melting point that of the original hydrogenated rosin.

As a new composition a heat-treated hydrogenated natural resincoinprising the residue obtained by distillation of a'hydrogenated rosin saturated to the extent of between. 25% and 100% of the double bonds and subsequently heat-treated at a temperature within the range of from about 250 C. to about 350 C. for a period of from about -l'1cur r,o about 10 hours, the said distillation being sufficient to remove the light oils and volatile resin decomposition products and insufficient to remove more than about 25% by weight of the product, said resin being characterized by having a lower melting point than that of the original hydrogenated rosin.

8. As a new composition a heat-treated hydrogenated natural resin comprising the residue obtained by distillation of a hydrogenated rosin saturated to the extent of between 50% and of the double bonds and subsequently heat-treated at a temperature within the range of from about 250 C. to about 350 C. for a period of from about hour to about 10 hours, the said distillation being sufiicient to remove the light oils and volatile resin decomposition products and insufficient to remove more than about 25% by weight of the v product, said resin being characterized by having a lower melting point than that of the original hydrogenated rosin.

the double bonds and subsequently heat-treated 10 at a temperature within the range of from about 250 C. to about 350 C. for a period of from about hour to about 10 hours, the said distillation being suifioient to remove the light. oils and volatile resin decomposition products and insuiiicient to remove more than about 5% to about 15% by weight of the product, said resin being characterized by having a lower melting point than that of the original hydrogenated rosin.

- 10. As a new composition a heat-treated hydrogenated natural resin comprising the residue obtained by distillation of a hydrogenated rosin saturated to the extent of between 50% and 90% of the double bonds and subsequently heattreated at a temperature within the range of from about 250 C. to about 350 C(for a period of from about hour to about 10 hours, the said distillation being suificient to remove the light oils and-volatile resin decomposition products and insufficient to remove more than about 5% to about 15% by weight of the product, by spraying with a gas which is inert to the reaction mixture, said resin being characterizedby having a lower melting point than that of I said original hydrogenated rosin.

JACOB M. SC HAN'IZ. 

